Change direnv example to upload $env.PATH as a list

[Gryff]

First of all thanks for the direnv example!
It got me unblocked, but I missed that I couldn't see the path in the list format when I typed $env.PATH.

I'm new to nushell, so if there's a better way to do this than the no_changes changes thing, let me know and I'll change it. I couldn't find like a $my_thing | is-not-empty.

[fdncred]

I personally don't like things like upsert PATH {|it| $it.PATH | split row ":" }. To me, it's not useful to name the closure variable with a generic variable that means nothing. I prefer my variables to have meaning like upsert PATH {|direnv_result| $direnv_result.PATH | split row ":" }.

If we're just going for brevity, then you could do upsert PATH { $in.PATH | split row : }.

But let's land this anyway. Thanks.